When ordering membrane switches with an LED option, specify which LEDs are fitted in this order, which positions are reserved only, and which are explicitly left unpopulated. Link each choice to the corresponding BOM, drawing and approved sample. A reserved light-transmitting area, circuit connection or mounting space does not mean an LED is supplied. An unpopulated unit can be accepted against that configuration only when it is explicitly permitted by the approved order. This article covers component procurement for ordinary, non-safety equipment, not medical applications, safety-related alarms or equipment release.
In its November 2, 2026 PolySense accessories announcement, ZOLL distinguished the basic WatchPAT 400 platform from the expanded testing configuration with the full PolySense kit. The company planned U.S. accessory availability for early January 2027. This is recent equipment-accessory news, not a statement that the accessories are already on sale. The announcement does not disclose membrane-switch construction or identify Baoshengda as a supplier.
A platform may support expanded functions while the actual delivery depends on the ordered configuration. If your own ordinary instrument project separately purchases membrane switches with optional LEDs, distinguish a position reserved for a later LED from an LED fitted in this batch through separate supply records. The following is a procurement method for your own project, not an analysis of the news device or an application of its medical clearance.
Replace “reserved” with an identifiable object
If an RFQ says only “supports LEDs,” ask the supplier to state whether it reserves a light-transmitting area in the overlay, a circuit connection, component mounting space, or includes actual component assembly. These are not interchangeable. When a feature is reserved but not populated in this order, identify its position, what remains, and the components excluded. The designer and manufacturer must confirm feasibility for the actual construction.
Nicomatic's SMD LED manufacturer documentation lists discrete LEDs for membrane switches and distinguishes packages and part numbers. An LED choice therefore needs a specific component identity; a colored circle on an overlay does not establish that a particular LED is fitted inside. This documentation does not prove that Baoshengda uses Nicomatic components or can implement any proposed reserved-position design.
Record fitted and unpopulated choices explicitly on the order line
The following is a suggested configuration response for this project, not an industry standard or Baoshengda's fixed product list. Link every row to the current drawing and BOM. Keep unresolved items unconfirmed; “optional” is not a record of the option selected for this order.
| Configuration for this order | What the order and BOM record | How samples and incoming goods correspond |
|---|---|---|
| LEDs fitted | Component positions, full part numbers, colors, quantities and assembly scope; who provides power and drivers | Match the approved sample to the population list; check actual illumination under agreed conditions, not from artwork showing translucent areas |
| Reserved only; not populated in this order | List retained windows, circuitry or space, and components explicitly not fitted; identify exclusions such as drivers | Check retained construction against the approved unpopulated configuration; mark illumination tests not applicable to this configuration with the basis, not as passed |
| Option explicitly removed | Identify components and associated construction removed under the approved design; do not assume it is identical to the reserved version | Use the corresponding revision and sample; similar appearance does not prove interchangeability with the reserved version |
| Configuration unresolved | Identify positions awaiting confirmation, the responsible party and the effect on this quotation and order | Do not approve another configuration's sample or report as this order's basis while the choice remains unresolved |
For example, suppose two order lines use the same appearance artwork: one requires fitted LEDs and the other retains only the light-transmitting areas. Calling both “with LED functionality” loses the distinction. Each should point to its population list or explicitly unpopulated configuration. This is an illustrative purchasing example, not a customer case, and does not establish that both versions can share any construction.
An unpopulated version needs its own confirmation scope
Leaving out LEDs does not automatically leave every other construction detail unchanged. The project owner should confirm the unlit appearance of translucent areas, unused positions and support, the treatment of retained circuitry, and whether changes affect keys or assembly. Check only approved design requirements. This article does not provide instructions for shorting connections, adding soldered components or modifying equipment in the field.
Shenzhen Baoshengda Technology Co., Ltd.'s LED-backlit design review page (Chinese) calls for package, color, polarity, drive method and available thickness to be defined, together with the relationship between components, key loading, windows and light-blocking layers. When requesting a quotation from Baoshengda Technology, start with a position diagram and the assembly choices for this order, then ask the supplier to respond item by item on included scope. The public guide does not mean every order includes LEDs, a driver board or equipment-level illumination validation.
A graphic overlay or keypad overlay (Chinese) purchased as a surface-only part does not include switch circuitry. An indicator symbol on the artwork cannot establish that LEDs are supplied. For a metal-dome overlay used with the customer's PCB, separately identify who supplies the PCB, LEDs and driver; do not automatically describe it as a complete membrane-switch assembly.
Confirm later population as a new change
Returning to the news announcement's platform and full-accessory-kit condition, a part not supplied in this order cannot be recorded as received simply because the platform supports it. If your own project later converts a reserved version to an LED-populated version, reconfirm components, assembly, drivers, costs and affected verification scope. Approval of the original unpopulated sample covers that configuration only; it cannot validate future illumination results in advance.
If the light source and driver are still undecided, see EL and LED backlight design inputs. Responsibilities for active interfaces and indicator power are discussed separately in GPIO procurement electrical boundaries. This article addresses assembly choices on the order, not optical-technology comparisons or interface wiring.
Use the project contact page to share a photo or sketch identifying LED positions and the items to be fitted, reserved or removed in this order. Without a complete BOM, keep unresolved items open; link the current revisions when placing the formal order and approving samples. The English membrane-switch product page provides the product scope. The cover shows an existing site's sample with colored indicator circles, keys, tails and a lifted release liner. It does not establish internal LED quantities or part numbers, illumination results or this order's configuration.